We found this circuit in a 1956 Sylvania publication. It serves to monitor telegraph transmissions being placed next to the transmitter. The circuit is indicated for the range of 80 and 160 meters.
We found this circuit in an Analog Devices documentation from the 90s. The circuit is based on a...
This circuit turns off a load after an interval of 8 to 80 seconds adjusted on the potentiometer. The...
Found elsewhere in this section, this circuit is from the April 1971 Radio Electronics magazine. Note...